常染色体優性遺伝型錐体杆体ジストロフィの1家系

A pedigree of autosomal dominant cone-rod dystrophy

　常染色体優性遺伝型の錐体杆体ジストロフィ（以下CRD）と考えられる1家系を報告した。5人兄弟のうち42歳と49歳の2人が視力低下と夜盲を訴え，眼科学的検査でも同様の所見を示した。検眼鏡および螢光眼底造影検査で黄斑部における輪状の網膜色素上皮萎縮がみられた。視野検査では，ほぼ正常の周辺視野を伴った輪状暗点あるいは傍中心暗点を示した。また，色覚異常，暗順応最終閾値の上昇もみられた。Photopic ERG, scotopic ERG検査を量的に評価し，錐体反応が杆体反応に比べ，より障害されていた。彼らの母親は網膜色素変性症末期に類似した高度の網脈絡膜萎縮と著明な視野狭窄を示した。また，母方の伯母と祖父も同様の症状を訴えていた。

We identified a family with cone-rod dystrophy of probably autosomal dominant inheritance.Two brothers, aged 42 and 49 years, had been complaining of reduced vision and night blindness. Fundus-copic findings were similar in both and comprised ring-shaped pigment epithelial atrophy in the macular area. Visual field test showed ring scotoma or paracentral scotoma with grossly normal peripheral field.Dyschromatopsia and elevated final threshold on dark adaptometry were also present. Quantitative evalua-tion of photopic and scotopic ERGs indicated more reduction of cone than rod response. Their mother showed severe markedly constricted visual field and chorioretinal atrophy throughout the fundus suggesting terminal stage of retinitis pigmentosa. Their maternal aunt and grandfather were also allegedly affected.